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Tonga–Kermadec Subduction Zone
The Tonga–Kermadec subduction zone (also known as Kermadec–Tonga or Tonga–Kermadec-Hikurangi subduction zone) is a convergent plate boundary that stretches from the North Island of New Zealand northward. The formation of the Kermadec and Tonga plates started about 4–5 million years ago. Today, the eastern boundary of the Tonga plate is one of the fastest subduction zones, with a rate up to . The trench formed between the Tonga–Kermadec and Pacific plates is also home to the second deepest trench in the world, at about 10,800 m, as well as the longest chain of submerged volcanoes. Geological setting At the northern end of the zone the vector of the Pacific plate collision with the Australian changes to north–south from east–west, to the east of Fiji and south of Samoa. A number of microplates exist between the two major plates and host various back-arc structures of which the largest are the volcanic Tonga–Kermadec Ridge, the actively spreading Lau Basin and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kermadec And Tonga Plates
Kermadec or de Kermadec may refer to: Geography * Kermadec Islands, a subtropical island arc in the South Pacific Ocean northeast of New Zealand * Kermadec Plate, a long narrow tectonic plate located west of the Kermadec Trench * Kermadec Trench, one of Earth's deepest oceanic trenches, reaching a depth of 10047 m * Kermadec-Tonga subduction zone, a convergent plate boundary * Tonga-Kermadec Ridge, an oceanic ridge in the south-west Pacific Ocean People * Eugène de Kermadec (1899–1976), French painter * François Pierre Huon de Kermadec (1726–1787), French Navy officer * Gil de Kermadec (1922–2011), French tennis player * Jean-Marie Huon de Kermadec (1747–1796), French Navy officer * Jean-Michel Huon de Kermadec (1748–1792), French navigator * Liliane de Kermadec (1928–2020), French film director and screenwriter See also * ''Kermadecia ''Kermadecia'' is a genus of flowering plants in the family Proteaceae. The genus comprises eight species of rainforest trees fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tonga Plate
The Tonga plate is a small southwest Pacific tectonic plate or microplate. It is centered at approximately 19° S. latitude and 173° E. longitude. The plate is an elongated plate oriented NNE–SSW and is a northward continuation of the Kermadec linear zone north of New Zealand. The plate is bounded on the east and north by the Pacific plate, on the northwest by the Niuafo’ou microplate, on the west and south by the Indo-Australian plate. The Tonga plate is subducting the Pacific plate along the Tonga Trench. This subduction turns into a transform fault A transform fault or transform boundary, is a fault (geology), fault along a plate boundary where the motion (physics), motion is predominantly Horizontal plane, horizontal. It ends abruptly where it connects to another plate boundary, either an ... boundary north of Tonga. An active rift or spreading center separates the Tonga plate from the Australian plate and the Niuafo’ou microplate to the west. The Tonga plate is se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mariana Trench
The Mariana Trench is an oceanic trench located in the western Pacific Ocean, about east of the Mariana Islands; it is the deep sea, deepest oceanic trench on Earth. It is crescent-shaped and measures about in length and in width. The maximum known depth is at the southern end of a small slot-shaped valley in its floor known as the Challenger Deep. The deepest point of the trench is more than farther from sea level than the peak of Mount Everest. At the bottom of the trench, the water column above exerts a pressure of , more than 1,071 times the standard atmospheric pressure at sea level. At this pressure, the density of water is increased by 4.96%. The temperature at the bottom is . In 2009, the Mariana Trench was established as a National monument (United States), US National Monument, Mariana Trench Marine National Monument. One-celled organisms called monothalamea have been found in the trench at a record depth of below the sea surface by researchers from the Scrip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Challenger Deep
The Challenger Deep is the List of submarine topographical features#List of oceanic trenches, deepest known point of the seabed of Earth, located in the western Pacific Ocean at the southern end of the Mariana Trench, in the ocean territory of the Federated States of Micronesia. The General Bathymetric Chart of the Oceans, GEBCO Gazetteer of Undersea Feature Names indicates that the feature is situated at and has an approximated maximum depth of below sea level. A subsequent study revised the value to at a 95% confidence interval. However, both the precise geographic location and depth remain ambiguous, with contemporary measurements ranging from . The depression is named after the British Royal Navy survey ships , whose Challenger expedition, expedition of 1872–1876 first located it, and HMS Challenger (1931), HMS ''Challenger II'', whose expedition of 1950–1952 established its record-setting depth. The first descent by any vehicle was conducted by the United States N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tonga Trench
The Tonga Trench is an oceanic trench located in the southwestern Pacific Ocean. It is the deepest trench in the Southern hemisphere and the second deepest on Earth after the Mariana Trench. The fastest plate-tectonic velocity on Earth is occurring at this location, as the Pacific plate is being Subduction, subducted westward in the trench. Horizon Deep The deepest point of the Tonga Trench, the Horizon Deep at , is deep, making it the deepest point in the Southern Hemisphere and the second deepest on Earth after the Challenger Deep in the Mariana Trench. It is named for the research vessel RV Horizon, ''Horizon'' of the Scripps Institution of Oceanography, the crew of which found the deep in December 1952. As one of the deepest Hadal zone, hadal trenches, the sediment of the Horizon Deep harbours a community of Nematode, roundworms. A 2016 study found that the abundance of individuals in this community is six times greater than it is at a site on the trench edge at approximate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kermadec Trench
The Kermadec Trench is a linear ocean trench in the south Pacific Ocean. It stretches about from the Louisville Seamount Chain in the north (26°S) to the Hikurangi Plateau in the south (37°S), north-east of New Zealand's North Island. Together with the Tonga Trench to the north, it forms the -long, near-linear Kermadec-Tonga subduction system, which began to evolve in the Eocene when the Pacific plate started to subduct beneath the Australian plate. Convergence rates along this subduction system are among the fastest on Earth, /yr in the north and /yr in the south. Geology The Kermadec Trench is one of Earth's deepest oceanic trenches, reaching a depth of . Formed by the subduction of the Pacific plate under the Indo-Australian plate, it runs parallel with and to the east of the Kermadec Ridge and island arc. The Tonga Trench marks the continuation of subduction to the north. The Kermadec Trench has a southern continuation in the turbidite-filled Hikurangi Trough, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hikurangi Trough
The Hikurangi Trough (previously known as the Hikurangi Trench) is a sea floor feature of the Pacific Ocean off the north-east South Island and the east coast of the North Island of New Zealand. It has been forming for about 25 million years and is turbidite-filled, particularly in its south. This characteristic can be used to distinguish it from the sediment-poor and deeper Kermadec Trench, which is its continuation to the north. Sediment currently passing through the trough represents about 0.5% of the total sediment input to the world oceans. The trough has deep-sea chemosynthetic ecosystems that are unique. Geography Although shallower than the trenches north of it, the Hikurangi Trough reaches depths of as close as from shore. The southern trough structure is wide off the coast of northern Canterbury with an initial local depth of about , and towards its northern portions it has structures more like those found in oceanic trenches. The trough widens about the latitude ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction
Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second plate, the heavier plate dives beneath the other and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with rates of convergence as high as 11 cm/year. Subduction is possible because the cold and rigid oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle. Once initiated, stable subduction is driven mostly by the negative buoyancy of the dense subducting lithosphere. The down-going slab sinks into the mantle largely under its own ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiordland
Fiordland (, "The Pit of Tattooing", and also translated as "the Shadowlands"), is a non-administrative geographical region of New Zealand in the south-western corner of the South Island, comprising the western third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lakes, and its steep, glacier-carved and now ocean-flooded western valleys. The name "Fiordland" derives from the New Zealand English spelling of the Scandinavian word for steep glacial valleys, "fjord". The geographic area of Fiordland is dominated by, and roughly coterminous with, Fiordland National Park, New Zealand's largest national park. Due to the often steep terrain and high amount of rainfall supporting dense vegetation, the interior of the Fiordland region is largely inaccessible. As a result, Fiordland was never subjected to notable logging operations, and even attempts at whaling, seal hunting, and mining were on a small scale and short-lived, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
